If you want to know more about iSCSI, we’ll have to talk a bit about SCSI. That seems logical! SCSI stands for Small Computer System Interface and is a bus. Basically, that’s a protocol to carry data. Historically, SCSI has always been related to a lot of very different kind of devices (from floppy readers to scanners) but storage got a particular place in its history. For instance, the father of SCSI, Al Shugart, was an engineer specialized in hard drives. This protocol allows fast and smart data transfers but is sometimes a bit complicated, especially when we talk about connections: a lot of specific hardware is required.
iSCSI allows SCSI commands to be transported through any IP network. That’s where the small “I” comes from. Basically, it’s like carrying a letter (the SCSI command) all around the world within a plane (the iSCI protocol). You can choose domestic flights (local networks) or international flights (Internet) as a destination, it does not matter: you just need to buy the proper ticket (iSCSI configuration).
Initiators and Targets: the essential concept
An iSCSI imitator is the device which is going to send the commands all over the network. It can be software of a particular piece of hardware. In daily usage, the initiator would be your computer which is going to “initiate” the connection with the iSCSI drive by giving various orders through the network.
So, if you followed correctly, you’ve already guess that the iSCSI target is your NAS! The target will receive several orders from the computer and send back the requested data. Configuring initiators and targets is a very easy task once you know where to go. To help you, Thecus provided some very efficient how-to guide in the Thecus Classroom on our website www.thecus.com.
But why should I use iSCSI?
That’s a good point. In storage, the essential point is giving orders and getting response from your server. To do so, with acceptable performances and safety, engineers don’t have that many solutions. IF you don’t want to do direct, classical and old-fashioned connections, you can use Fiber Channel or iSCSI. Fiber Channel is a very efficient way to connect your storage units in your network. But it needs specific wires, hardware and skills. It can really be deterrent for home usage or SMB. iSCSI brings a lot of advantages on a table: less costly, efficient, easy to start and so on. The main reason is iSCSI does not need specific network: just a basic IP address-based network should do the trick. And that mean it’s also working on the Internet! With proper configuration, you can create a target/initiator couple anywhere in the world.
Wait a second… what’s FCoE?
We talked a bit about Fiber Channel, saying it requires specific cables and hardware. Aware of this issue, people start developing FCoE. Basically, it’s like iSCSI but using Fiber Channel protocol with a different carrier (iSCSI uses TCP/IP while FCoE uses Ethernet). iSCSI is more targeted to home and SMB usages while FCoE seems more practical for enterprises and data centers. However, the struggle between those two standards is hard and so far pretty balanced. Adopting FCoE or iSCSI greatly depends on your skills, budget, existing infrastructure and if you got a doubt, feel free to ask an IT professional about it!
Youtube: Discover iSCSI and how to use it with a Thecus® NAS.
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